ZYN and Microplastics: What the FDA Controversy Is About

By PouchGuide Editorial Team · Published September 28, 2026

In July 2026, a former FDA scientist went public with a claim that got a lot of attention: the agency authorized ZYN without knowing exactly what the pouch is made of, and without assessing whether it could release microplastics. Here’s what’s been claimed, what the FDA said, and what it means for ZYN users.

What’s being claimed

According to reporting by STAT News (July 14, 2026):

• Christy Leppanen, a toxicologist with nearly 30 years of experience, joined the FDA’s Center for Tobacco Products in 2021. She led a project on potential microplastics exposure and was assigned to review ZYN’s environmental assessment.
• She ran informal tests on ZYN pouches bought at a store: soaking them in saliva, heating them, crushing them and sucking on them. “They did not dissolve.”
• She says the pouch material resembles cellulose acetate, the material used in cigarette filters.
• Her central allegation: the FDA authorized ZYN “without knowing what the pouch itself is made of” and without evaluating whether the material could shed microplastics during use. “Fundamentally, we did not do a proper assessment,” she told STAT.

What the FDA and PMI said

• An FDA spokesperson said the agency’s review “did not identify new or additional concerns about the ingredients/materials”, but didn’t specify what ZYN pouches are made of. STAT reported the agency later acknowledged that its assessment “does not address the potential effects of plastics and microplastics.”
• PMI and Swedish Match didn’t respond to STAT’s questions. PMI’s website describes the pouch as cellulose, without more detail.

The FDA authorized 20 ZYN products for sale in January 2025, and granted them a modified-risk order in June 2026 (see our explainer).

What’s actually known about the health risk

This is the key point: no study has shown that ZYN pouches release microplastics into users’ bodies, or that they cause harm this way. What exists is:

• one scientist’s informal tests showing the pouch material doesn’t dissolve
• her view that the material resembles cellulose acetate
• broader research showing microplastics can build up in human organs, which experts quoted by STAT said is why the question matters

So the honest status is: an open question the FDA didn’t formally assess, not a demonstrated harm. It would take proper testing of the pouch material, and of what it releases during realistic use, to answer it.

Why this matters

• Pouches are used for hours a day. If the material did shed particles, exposure would be frequent and long-term.
• Used pouches become litter. A material that doesn’t break down easily is an environmental issue too (see pouches and the environment).
• It highlights what FDA authorization covers. Authorization isn’t a guarantee that every aspect of a product has been studied (see how FDA review works).

What you can do if you’re concerned

• Use fewer pouches, for shorter times. That reduces exposure to everything in the pouch, including nicotine (see how long to keep a ZYN in).
• Don’t chew or suck hard on pouches, and don’t swallow them.
• Dispose of used pouches in a bin, not on the ground.
• Consider cutting down or quitting. Our quitting guide can help.

Bottom line

A former FDA toxicologist says the agency authorized ZYN without identifying the pouch material, which she believes resembles cigarette-filter cellulose acetate, or assessing microplastic release. The FDA says its review found no new concerns, but acknowledged it didn’t address microplastics. No study has shown ZYN pouches release microplastics into users or cause harm, so this is an open question, not an established risk. We’ll update this post if the FDA or independent researchers publish testing.